Extreme ultraviolet (EUV) light is high-energy ultraviolet radiation generally defined to be electromagnetic radiation having wavelengths ranging between about 10 nm to about 120 nm. EUV may be artificially generated by laser produced plasma.
In a conventional laser produced plasma (LPP) EUV generator, a EUV light generating substance may be released as droplets in to a chamber. A laser beam may then irradiate the droplets inside the chamber. When the laser beam irradiates a droplet, the droplet is excited to a plasma state and generates EUV light. However, a portion of the droplet may fragment and scatter during this process, forming debris. Such debris may not transform to plasma, and may remain inside the chamber.
Therein lies a need for a method and apparatus for generating EUV light via laser produced plasma with reduced debris.